[Bug 735378] gstrtpjitterbuffer: requests retransmission periodically when no needed

[GStreamer (bugzilla.gnome.org)]

https://bugzilla.gnome.org/show_bug.cgi?id=735378
  GStreamer | gst-plugins-good | 1.3.3

Miguel París Díaz <mparisdiaz> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|RESOLVED                    |UNCONFIRMED
         Resolution|NOTABUG                     |

--- Comment #3 from Miguel París Díaz <mparisdiaz at gmail.com> 2014-08-26 16:26:15 UTC ---
Hello again,
I have been thinking about my problem and it is derived when the network jitter
approaches 0 (for example in a lo network, where I am doing my tests).

This causes retransmission requests for packets not generated yet by the
sender, for example in the case where the sender are capturing and enconding
video, which can add oscillations in the frames generation ("media jitter").

CURRENT TIMEOUT CALC.
JitterBuffer set the time out as follow (see [1] and [2]):
  timeout = expected + delay;

where:
  expected = dts + priv->packet_spacing;

  and delay depends on the config:
    if (priv->rtx_delay == -1) {
      if (priv->avg_jitter == 0)
        delay = DEFAULT_AUTO_RTX_DELAY;
      else
        /* jitter is in nanoseconds, 2x jitter is a good margin */
        delay = priv->avg_jitter * 2;
    } else {
      delay = priv->rtx_delay * GST_MSECOND;
    }

NEW TIMEOUT CALC. PROPOSAL
If we set “rtx-delay”, we loss the 2x jitter usage for the delay, which it is
useful.
So, I propose a new attr named "rtx-min-delay", which set the minimum time in
ms to wait before sending retransmission event.
I attach a patch where you can see it with more details.

Refs
[1]
http://cgit.freedesktop.org/gstreamer/gst-plugins-good/tree/gst/rtpmanager/gstrtpjitterbuffer.c?id=1.3.3#n1883
[2]
http://cgit.freedesktop.org/gstreamer/gst-plugins-good/tree/gst/rtpmanager/gstrtpjitterbuffer.c?id=1.3.3#n1696

-- 
Configure bugmail: https://bugzilla.gnome.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the QA contact for the bug.
You are the assignee for the bug.